Re: [Qemu-devel] [PATCH 10/12] virtio-net: multiqueue support

[Wanlong Gao]

On 01/08/2013 05:51 PM, Jason Wang wrote:
> On 01/08/2013 05:49 PM, Wanlong Gao wrote:
>> On 01/08/2013 05:29 PM, Jason Wang wrote:
>>> On 01/08/2013 05:07 PM, Wanlong Gao wrote:
>>>> On 12/28/2012 06:32 PM, Jason Wang wrote:
>>>>> +    } else if (nc->peer->info->type !=  NET_CLIENT_OPTIONS_KIND_TAP) {
>>>>> +        ret = -1;
>>>>> +    } else {
>>>>> +        ret = tap_detach(nc->peer);
>>>>> +    }
>>>>> +
>>>>> +    return ret;
>>>>> +}
>>>>> +
>>>>> +static void virtio_net_set_queues(VirtIONet *n)
>>>>> +{
>>>>> +    int i;
>>>>> +
>>>>> +    for (i = 0; i < n->max_queues; i++) {
>>>>> +        if (i < n->curr_queues) {
>>>>> +            assert(!peer_attach(n, i));
>>>>> +        } else {
>>>>> +            assert(!peer_detach(n, i));
>>>> I got a assert here,
>>>> qemu-system-x86_64: /work/git/qemu/hw/virtio-net.c:330: 
>>>> virtio_net_set_queues: Assertion `!peer_detach(n, i)' failed.
>>>>
>>>> Any thoughts?
>>>>
>>>> Thanks,
>>>> Wanlong Gao
>>> Thanks for the testing, which steps or cases did you met this assertion,
>>> migration, reboot or just changing the number of virtqueues?
>> I use the 3.8-rc2 to test it again, I saw this tag has the multi-tap support.
>>
>> I just can't start the QEMU use  -netdev 
>> tap,id=hostnet0,queues=2,fd=%d,fd=%d -device 
>> virtio-net-pci,netdev=hostnet0,id=net0,mac=52:54:00:ce:7b:29,bus=pci.0,addr=0x3
>>
>> I pre-opened two tap fds, did I missing something?
> 
> Nothing missed :) It should work.
> 
> Could you please try not use fd=X and let qemu to create the file
> descriptors by itself? Btw, how did you create the two tap fds?

Can it create descriptors itself? I get 
qemu-system-x86_64: -netdev tap,id=hostnet0,queues=2: Device 'tap' could not be 
initialized

I create the tap fd like this, and dup create the second fd, third fd, right?

        int tap_fd = open("/dev/net/tun", O_RDWR);
        int vhost_fd = open("/dev/vhost-net", O_RDWR);
        char *tap_name = "tap";
        char cmd[2048];
        char brctl[256];
        char netup[256];
        struct ifreq ifr;
        if (tap_fd < 0) {
                printf("open tun device failed\n");
                return -1;
        }
        if (vhost_fd < 0) {
                printf("open vhost-net device failed\n");
                return -1;
        }
        memset(&ifr, 0, sizeof(ifr));
        memcpy(ifr.ifr_name, tap_name, sizeof(tap_name));
        ifr.ifr_flags = IFF_TAP | IFF_NO_PI;

        /*
         * setup tap net device
         */
        if (ioctl(tap_fd, TUNSETIFF, &ifr) < 0) {
                printf("setup tap net device failed\n");
                return -1;
        }

        sprintf(brctl, "brctl addif virbr0 %s", tap_name);
        sprintf(netup, "ifconfig %s up", tap_name);
        system(brctl);
        system(netup);

Thanks,
Wanlong Gao


> 
> Thanks
>>
>> Thanks,
>> Wanlong Gao
>>
>>>>> +        }
>>>>> +    }
>>>>> +}
>>>>> +
>>>>> +static void virtio_net_set_multiqueue(VirtIONet *n, int multiqueue, int 
>>>>> ctrl);
>>>>> +
>>>> --
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>>>
>>
> 
>